The invention relates to a remote control method for operating an unmanned air vehicle (also called an unmanned airborne vehicle and an unmanned aerial vehicle), and to an unmanned air vehicle for performing the remote control method.
Unmanned air vehicle (UAV) missions are essentially based on pre-programmed flight paths. The planning of the flight paths requires precise knowledge of the terrain to be flown over and the expected threat of anti-aircraft defense. Very precise knowledge of the target area is particularly necessary in order to carry out target combat. This often occurs with additional support of final approach sensors that operate by comparing or matching images. These sensors thus require exact images of the targets and, under certain circumstances, images from various perspectives may be required. With preprogrammed flights it is impossible to react to unforeseen events.
The execution of such difficult tasks can be significantly improved if the UAV is remote-control guided via a radio wave transmission link, whereby the xe2x80x9cpilotxe2x80x9d operates the UAV from a remotely-situated control station. The control station can be located either on the ground or in flight in a manned aircraft. The remote control is carried out with the aid of a television or video image. The image is recorded by a camera in the unmanned UAV and transmitted to the control station where it is presented in a suitable manner (see, e.g., Predator; UAV Annual Report FY 1997, Nov. 6, 1997, page 5).
The above conventional method has the disadvantage that it depends on the reliability of the radio wave link. Loss of radio contact would, as is known, bring the UAV into an uncontrolled flight phase, which eventually results in the UAV crashing.
It is an object of the invention to avoid the occurrence of an uncontrolled flight of a remotely controlled UAV in the case of loss of radio contact.
The above objects have been achieved according to the invention in a method of remotely controlling an unmanned air vehicle (UAV) from a remote control station by radio transmitting control signals from the control station to the UAV and radio transmitting images from the UAV to the control station. According to the method, the UAV initially flies on a pre-programmed safety route, and then, as required, the UAV is guided by remote control to a flight path by correspondingly radio transmitting appropriate control signals from the control station to the UAV. In the event of an interruption of the radio contact between the control station and the UAV, then the UAV will fly on a substitute route calculated on-board the UAV using on-board equipment of the UAV, without active remote control intervention from the control station.
The invention is based on a method of continuing the flight of the UAV in the case of loss of radio contact by means of a substitute flight program calculated on-board. In this way, the threatened loss of the UAV can be avoided in an advantageous manner: and the mission can possibly be successfully concluded despite the radio interference.